Integrated circuit and method of manufacturing same

ABSTRACT

A method includes positioning a first set of conductive traces in a first direction, manufacturing a second set of conductive traces by a first mask pattern, and electrically coupling, by at least a first via, at least one conductive trace of the first set of conductive traces to at least one conductive trace of the second set of conductive traces. The first set of conductive traces is in a first layer of an integrated circuit. The second set of conductive traces is in a second direction different from the first direction. The second set of conductive traces is in a second layer of the integrated circuit. The second layer is different from the first layer. A conductive trace of the second set of conductive traces is part of a first dummy transistor.

PRIORITY CLAIM

The present application is a continuation of U.S. application Ser. No.14/464,407, filed Aug. 20, 2014, which claims priority to U.S.Provisional Application No. 62/003,395, filed May 27, 2014, which areincorporated herein by reference in their entireties.

BACKGROUND

Integrated circuits (ICs) are often designed with active devices such astransistors, resistors and capacitors connected by conductive traces,such as metal lines and polysilicon lines, to form circuits. The activedevices in ICs are formed by a photolithographic process that includesuse of photoresists, photolithographic masks (masks), specialized lightsources and various etchants. Increasingly dense ICs have numerousbenefits in terms of speed, functionality and cost, but causeincreasingly difficult design and fabrication problems.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1A is a diagram of a double patterned cell with a horizontalconductive trace orientation in a layout design for integrated circuits,in accordance with some embodiments.

FIG. 1B is a diagram of a double patterned cell with a verticalconductive trace orientation in a layout design for integrated circuits,in accordance with some embodiments.

FIG. 2A is a diagram of a single patterned cell with a horizontalconductive trace orientation in a layout design for integrated circuits,in accordance with some embodiments.

FIG. 2B is a diagram of a single patterned cell with a verticalconductive trace orientation in a layout design for integrated circuits,in accordance with some embodiments.

FIG. 3A is diagram of a double patterned cell in a layout design forintegrated circuits, in accordance with some embodiments.

FIG. 3B is diagram of a double patterned cell in a layout design forintegrated circuits, in accordance with some embodiments.

FIG. 4 is circuit diagram of a transmission gate corresponding to alayout design for integrated circuits, in accordance with someembodiments.

FIG. 5 is diagram of a layout design with a transmission gate cell forintegrated circuits, in accordance with some embodiments.

FIG. 6 is diagram of a layout design with a transmission gate cell forintegrated circuits, in accordance with some embodiments.

FIG. 7 is diagram of a layout design with a transmission gate cell forintegrated circuits, in accordance with some embodiments.

FIG. 8 is diagram of a layout design with a transmission gate cell forintegrated circuits, in accordance with some embodiments.

FIG. 9 is diagram of a layout design with a transmission gate cell forintegrated circuits, in accordance with some embodiments.

FIG. 10 is diagram of a layout design with a transmission gate cell forintegrated circuits, in accordance with some embodiments.

FIG. 11 is diagram of a layout design with a transmission gate cell forintegrated circuits, in accordance with some embodiments.

FIG. 12 is diagram of a layout design with a transmission gate cell forintegrated circuits, in accordance with some embodiments.

FIG. 13 is diagram of a layout design with a transmission gate cell forintegrated circuits, in accordance with some embodiments.

FIG. 14 is diagram of a layout design with a transmission gate cell forintegrated circuits, in accordance with some embodiments.

FIG. 15 is diagram of a layout design with a transmission gate cell forintegrated circuits, in accordance with some embodiments.

FIG. 16 is a flow chart of a method of layout design for integratedcircuits, in accordance with some embodiments.

FIG. 17 is a block diagram of a computer system portion of a layoutdesign for integrated circuits system, in accordance with someembodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Over time, increasingly dense ICs incorporating progressively smallerphysical dimensions have correspondingly made many aspects of IC designand fabrication difficult or even impossible with prior methods. In someembodiments, improved IC design and fabrication methods include a systemand method of layout design for ICs that increase packing efficiency ofconductive traces, such as metal lines in metal layers created by BEOLprocesses.

The IC fabrication process is often considered to include afront-end-of-line (FEOL) portion, a middle-end-of-line (MEOL) portion,also called a Middle-Of-The-Line (MOL) portion, and a back-end-of-line(BEOL) portion. FEOL is the first portion of IC fabrication whereinindividual active devices are patterned on a semiconductor wafer. FEOLprocesses include: selecting the type of semiconductor wafer to be used;chemical-mechanical planarization and cleaning of the wafer; shallowtrench isolation (STI); well formation, gate module formation, andsource and drain creation. FEOL does not include the deposition of metalinterconnect layers. MEOL processes occur after FEOL processes andinclude gate contact formation and under bump metallization (UBM)processes.

BEOL is the final portion of the IC fabrication process where theindividual devices (transistors, capacitors, resistors, etc.) areinterconnected with vias and conductive traces, e.g., metal lines. BEOLgenerally begins when the first layer of metal is deposited and includescontacts, insulating layers (dielectrics), metal levels, and bondingsites for chip-to-package connections. In some embodiments, ten or moremetal layers are added in the BEOL portion.

In some embodiments, the system and method of layout design for ICsincreases packing efficiency of conductive traces, such as metal linesin metal layers created by BEOL processes, by routing all metal lines inone direction on each metal layer. Routing all metal lines in onedirection on each metal layer enables greater packing density through amore efficient packing of conductive traces. Routing all metal lines inone direction also makes it possible to relax pitch requirements betweenconductive traces, as set forth by one or more design rules, becausemetal structures having metal lines routed in one direction have aregular pattern that reduces the risk of manufacturing or processerrors. In some embodiments, a double patterning process creates sets ofmetal lines all oriented in a single direction.

FIG. 1A is a diagram of a double patterned cell with a horizontalconductive trace orientation in a layout design for integrated circuits100, in accordance with some embodiments. A first set of conductivetraces 102 is oriented in a single direction. In some embodiments, thefirst set of conductive traces 102 is oriented in a horizontal directionwith respect to the page orientation. In some embodiments, theconductive traces in the first set of conductive traces 102 are parallelmetal lines in the same metal layer. As used herein the term “line”includes one or more line segments. The first set of conductive traces102 is formed by photolithographic techniques using a first mask. Pitchis the spacing between repeating portions of adjacent conductive traces,such as similarly, repetitively positioned corners of adjacentconductive traces. The first mask, and correspondingly, the first set ofconductive traces 102, has a predetermined pitch.

A second set of conductive traces 104 is oriented in the same directionas the first set of conductive traces 102. In some embodiments, thesecond set of conductive traces 102 is oriented in a horizontaldirection. In some embodiments, the conductive traces in the second setof conductive traces 104 are parallel metal lines in the same metallayer. The second set of conductive traces 102 is formed byphotolithographic techniques using a second mask. The second mask, andcorrespondingly, the second set of conductive traces 104, has apredetermined pitch. In some embodiments, the pitch of the first maskand the pitch of the second mask are the same. Furthermore, the secondmask is positioned such that the second mask is offset with respect tothe first mask by less than the pitch for the first set of conductivetraces 102. Together, the first set of conductive traces 102 and thesecond set of conductive traces 104 are formed by double patterning.Double patterning is the formation of features on a layer with twooffset masks to create features smaller than a pitch of either mask.Double patterning is performed in the fabrication of ICs to increase thedensity of features patterned by the masks beyond that enabled by layersformed with a single mask.

A set of metal-like defined (MD) conductive traces 106 in an MD layer isformed during the MEOL portion of the IC fabrication process. In someembodiments, the set of MD conductive traces 106 is conductive, butcomprises a greater percentage of nonmetal material compared to metalmaterial. In some embodiments, the set of MD conductive traces 106 isformed of a semiconductor using ion implantation sufficient to convertthe semiconductor into a conductor. A double patterned cell 108 includesthe set of MD conductive traces 106 formed during the MEOL portion of ICfabrication, and the first set of conductive traces 102 and the secondset of conductive traces 104 formed during the BEOL portion of ICfabrication. The cell 108 has one or more active devices formed andelectrically connected in the cell.

FIG. 1B is similar to FIG. 1A rotated by 90 degrees. A first set ofconductive traces 102′ corresponds to the first set of conductive traces102 (FIG. 1A) rotated 90 degrees, however, there are four conductivetraces in FIG. 1B. A second set of conductive traces 104′ corresponds tothe first set of conductive traces 104 (FIG. 1A) rotated 90 degrees,however, there are three conductive traces 104′ in FIG. 1B. A first setof MD conductive traces 106′ corresponds to the first set of MDconductive traces 106 (FIG. 1A) rotated 90 degrees, however, there aresix MD conductive traces 106′ in FIG. 1B. A double patterned cell 108′corresponds to the double patterned cell 108 (FIG. 1A) rotated 90degrees.

FIG. 2A is a diagram of a single patterned cell with a horizontalconductive trace orientation in a layout design for integrated circuits200, in accordance with some embodiments. A set of conductive traces 202is oriented in a single direction. In some embodiments, the set ofconductive traces 202 is oriented in a horizontal direction. In someembodiments, the conductive traces in the set of conductive traces 202are parallel metal lines in the same metal layer. In some embodiments, anumber of the conductive traces in the set of conductive traces 202 isgreater than 4. The set of conductive traces 202 is formed byphotolithographic techniques using a mask having a predetermined pitch.The set of conductive traces 202 is formed by single patterning. Singlepatterning is the formation of features on a layer with one mask.Conductive traces formed by single patterning typically have lowerdensities than conductive traces formed by double patterning.

A set of MD conductive traces 206 in an MD layer is formed during theMEOL portion of the IC fabrication process. In some embodiments, the setof MD conductive traces 206 is conductive, but comprises a greaterpercentage of nonmetal material compared to metal material. In someembodiments, the set of MD conductive traces 206 is formed of asemiconductor using ion implantation sufficient to convert thesemiconductor into a conductor. A single patterned cell 208 includes theset of MD conductive traces 206 formed during the MEOL portion of ICfabrication, and the set of conductive traces 202 formed during the BEOLportion of IC fabrication. The cell 208 has one or more active devicesformed and electrically connected in the cell.

FIG. 2B is similar to FIG. 2A rotated by 90 degrees. A first set ofconductive traces 202′ corresponds to the first set of conductive traces202 (FIG. 2A) rotated 90 degrees, however, there are seven conductivetraces in FIG. 2B. A first set of MD conductive traces 206′ correspondsto the first set of MD conductive traces 206 (FIG. 2A) rotated 90degrees, however, there are six MD conductive traces 206′ in FIG. 2B. Adouble patterned cell 208′ corresponds to the double patterned cell 208(FIG. 2A) rotated 90 degrees.

FIG. 3A is diagram of a double patterned cell 308 in a layout design forintegrated circuits 300, in accordance with some embodiments. A firstset of conductive traces 302 is oriented in a single direction. In someembodiments, the first set of conductive traces 302 includes aneven-numbered quantity of conductive traces 302 oriented in a horizontaldirection. In some embodiments, the conductive traces in the first setof conductive traces 302 are parallel metal lines in the same metallayer. The first set of conductive traces 302 is formed byphotolithographic techniques using a first mask. The first mask, andcorrespondingly, the first set of conductive traces 302, has apredetermined pitch. In some embodiments, the pitch ranges from about 80nanometers (nm) to about 100 nm.

A second set of conductive traces 304 is oriented in the same directionas the first set of conductive traces 302. In some embodiments, thesecond set of conductive traces 304 includes an even-numbered quantityof conductive traces 304 oriented in a horizontal direction. In someembodiments, the conductive traces in the second set of conductivetraces 304 are parallel metal lines in the same metal layer. The secondset of conductive traces 304 is formed by photolithographic techniquesusing a second mask. The second mask, and correspondingly, the secondset of conductive traces 304, has a predetermined pitch. In someembodiments, the pitch of the first mask is equal to the pitch of thesecond mask. In some embodiments, the pitch of the first mask and thepitch of the second mask ranges from about 80 nm to about 100 nm. Insome embodiments, the pitch of the second set of conductive traces 304ranges from about 80 nm to about 100 nm.

The second mask is positioned such that the second mask is offset withrespect to the first mask by less than the pitch for the first set ofconductive traces 302. The pitch of the first set of conductive traces302 to the second set of conductive traces 304 (i.e., the distancebetween the first set of conductive traces 302 and the second set ofconductive traces 304) ranges from about 40 nm to about 80 nm. Together,each of the first set of conductive traces 302 and the second set ofconductive traces 304 are formed by double patterning. Vias 306electrically connect conductive traces in the first set of conductivetraces 302 and the second set of conductive traces 304 to conductivetraces in one or more other layers.

Cell 308 includes a conductive trace 302 that is a power rail LB and aconductive trace 304 that is a power rail LA. Cell 308 has aneven-numbered total quantity of conductive traces 302 and 304 betweenthe power rail LB and the power rail

LA.

FIG. 3B is diagram of a double patterned cell 308′ in a layout designfor integrated circuits 300, in accordance with some embodiments. Doublepatterned cell 308′ is similar to double patterned cell 308, butincludes a different quantity of conductive traces. A first set ofconductive traces 302′ corresponds to the first set of conductive traces302 (FIG. 3A), however, there is an odd-numbered quantity of conductivetraces included in the first set of conductive traces 302′ in FIG. 3B. Asecond set of conductive traces 304′ corresponds to the second set ofconductive traces 304 (FIG. 3A), the second set of conductive traces304′ includes an even-numbered quantity of line segments. Vias 306′correspond to vias 306 (FIG. 3A) and electrically connect conductivetraces in the first set of conductive traces 302′ and the second set ofconductive traces 304′ to conductive traces in one or more other layerswithin cell 308′.

Cell 308′ includes a first conductive trace 302′ that is a first powerrail LB and a second conductive trace 302′ that is a second power railLB. Cell 308′ has an odd-numbered total quantity of conductive traces302′ and 304′ between the first power rail LB and the second power railLB.

FIG. 4 is a circuit diagram of a transmission gate corresponding to alayout design for integrated circuits 400, in accordance with someembodiments. A first positive-type metal oxide semiconductor (PMOS)transistor 402 includes a gate terminal A1, a drain (D) terminal and asource (S) terminal. A first negative-type metal oxide semiconductor(NMOS) transistor 404 includes a gate terminal B2, a D terminal and an Sterminal. The D terminal of the first PMOS transistor 402 iselectrically connected to the S terminal of the first NMOS transistor404 and the S terminal of the first PMOS transistor is electricallyconnected to the D terminal of the first NMOS transistor to form a firsttransistor pair.

A second PMOS transistor 406 includes a gate terminal B1, a D terminaland an S terminal. A second NMOS transistor 404 includes a gate terminalA2, a D terminal and an S terminal. The D terminal of the second PMOStransistor 406 is electrically connected to the S terminal of the secondNMOS transistor 408 and the S terminal of the second PMOS transistor iselectrically connected to the D terminal of the second NMOS transistorto form a second transistor pair.

Gate terminal A1 of first PMOS transistor 402 is electrically coupled togate terminal A2 of second NMOS transistor 408. Gate terminal B1 ofsecond PMOS transistor 406 is electrically coupled to gate terminal B2of first NMOS transistor 404. The S terminal of the first PMOStransistor 402 and the D terminal of the first NMOS transistor 404 areelectrically coupled to the D terminal of the second PMOS transistor 406and the S terminal of the second NMOS transistor 408 to form atransmission gate 400. In some embodiments, the transmission gate 400 isin a single cell.

FIG. 5 is diagram of a layout design with a transmission gate cell forintegrated circuits 500, in accordance with some embodiments. Thetransmission gate cell 500 corresponds to the transmission gate of FIG.4, e.g., a gate terminal A1 of a first PMOS transistor is electricallyconnected to a gate terminal A2 of a second NMOS transistor and a gateterminal B1 of a second PMOS transistor is electrically connected to agate terminal B2 of a first NMOS transistor. As used herein, the phrase“electrically connected” includes the phrase “conductively connected.”In some embodiments, the transmission gate cell 500 includes metal 1(M1) portions, MD 2 (MD2) portions, via 0 (V0) portions,metal-polysilicon connected (MP) portions, oxide definition (OD)portions, polysilicon (Poly) portions and cut polysilicon (CPO)portions. In some embodiments, the M1 portions are contained in part ofa metal layer in the transmission gate cell 500. In some embodiments,the M1 portions are part of the only metal layer in the transmissiongate cell 500. In some embodiments, the M1 portions are positioned inone direction by double patterning with a first mask pattern and asecond mask pattern.

In some embodiments, the Poly portions are also referred to as a set ofconductive features extending along a first predetermined direction in aconductive layer, i.e., the polysilicon layer. In some embodiments, theMD2 portions are also referred to as a set of conductive featuresextending along the first predetermined direction in a conductive layer,i.e., the MD2 layer. In some embodiments, the M1 portions are alsoreferred to as a set of conductive features extending along a secondpredetermined direction in a conductive layer, i.e., the M1 layer.

In some embodiments, the transmission gate cell 500 includes fourconductive traces in a first set of conductive traces 502 and threeconductive traces in a second set of conductive traces 504, equaling atotal of seven conductive traces. In some embodiments, the first set ofconductive traces 502 and the second set of conductive traces 504 aredouble patterned as M1 portions of a metal layer. In some embodiments,the first set of conductive traces 502 and the second set of conductivetraces 504 are double patterned as seven metal lines in M1 portions of ametal layer.

Gate terminals A1, A2, B1 and B2 are formed of Poly portions. Gateterminal A1 in a first Poly portion is electrically connected through afirst via V0_1 portion to a first M1 metal portion, the first M1 metalportion is electrically connected through a second via portion to an MD2portion, the MD2 portion is electrically connected through a third viaportion to a second M1 portion, the second M1 portion is electricallyconnected through a fourth via v0_4 to gate terminal A2 in a second Polyportion.

Gate terminal B1 in a third Poly portion is electrically connectedthrough a fifth via V0_2 portion to a third M1 metal portion, the thirdM1 metal portion is electrically connected through a sixth via portionto a fourth Poly portion, the fourth Poly portion is electricallyconnected through a seventh via portion to a fourth M1 portion, thefourth M1 portion is electrically connected through a eighth via v0_3 togate terminal B2 in a fourth Poly portion. In some embodiments, thetransmission gate cell 500 includes at least six Poly portions. In someembodiments, the transmission gate cell 500 includes ten Poly portions.

In some embodiments, the conductive traces in the first conductive layernumber five between a conductive trace electrically coupled to a powersupply voltage and a conductive trace electrically coupled to a groundvoltage, e.g., to form the transmission gate cell.

FIG. 6 is diagram of a layout design with a transmission gate cell forintegrated circuits 600, in accordance with some embodiments. Except asdescribed herein and illustrated in FIG. 6, the description hereinassociated with FIG. 5 is applicable to FIG. 6. In some embodiments, thetransmission gate cell 600 includes four conductive traces in a firstset of conductive traces 602 and three conductive traces in a second setof conductive traces 604, equaling a total of seven conductive traces.In some embodiments, the first set of conductive traces 602 and thesecond set of conductive traces 604 are double patterned as M1 portionsof a metal layer. In some embodiments, the first set of conductivetraces 602 and the second set of conductive traces 604 are doublepatterned as seven metal lines in M1 portions of a metal layer.

Gate terminals A1, A2, B1 and B2 are formed of Poly portions. Gateterminal Al in a first Poly portion is electrically connected through afirst via V0_1 portion to a first M1 metal portion, the first M1 metalportion is electrically connected through a second via portion to an MD2portion, the MD2 portion is electrically connected through a third viaportion to a second M1 portion, the second M1 portion is electricallyconnected through a fourth via v0_4 to gate terminal A2 in a second Polyportion.

Gate terminal B1 in a third Poly portion is electrically connectedthrough a fifth via V0_2 portion to a third M1 metal portion, the thirdM1 metal portion is electrically connected through a sixth via portionto a fourth Poly portion, the fourth Poly portion is electricallyconnected through a seventh via portion to a fourth M1 portion, thefourth M1 portion is electrically connected through a eighth via v0_3 togate terminal B2 in a fourth Poly portion. In some embodiments, thetransmission gate cell 600 includes at least six Poly portions. In someembodiments, the transmission gate cell 600 includes seven Polyportions.

FIG. 7 is diagram of a layout design with a transmission gate cell forintegrated circuits 700, in accordance with some embodiments. Except asdescribed herein and illustrated in FIG. 7, the description hereinassociated with FIG. 5 is applicable to FIG. 7. In some embodiments, thetransmission gate cell 700 includes two conductive traces in a first setof conductive traces 702 and two conductive traces in a second set ofconductive traces 704, equating to a total of four conductive traces. Insome embodiments, the first set of conductive traces 702 and the secondset of conductive traces 704 are double patterned as M1 portions of ametal layer. In some embodiments, the first set of conductive traces 702and the second set of conductive traces 704 are double patterned as fourmetal lines in M1 portions of a metal layer.

Gate terminals A1, A2, B1 and B2 are formed of Poly portions. Gateterminal Al in a first Poly portion is electrically connected through afirst via V0_1 portion to a first M1 metal portion, the first M1 metalportion is electrically connected through a second via portion to an MD2portion, the MD2 portion is electrically connected through a third viaportion to a second M1 portion, the second M1 portion is electricallyconnected through a fourth via v0_4 to gate terminal A2 in a second Polyportion.

Gate terminal B1 in a third Poly portion is electrically connectedthrough a fifth via V0_2 portion to a third M1 metal portion, the thirdM1 metal portion is electrically connected through a sixth via portionto a fourth Poly portion, the fourth Poly portion is electricallyconnected through a seventh via portion to a fourth M1 portion, thefourth M1 portion is electrically connected through a eighth via v0_3 togate terminal B2 in a fourth Poly portion. In some embodiments, thetransmission gate cell 700 includes at least six Poly portions. In someembodiments, the transmission gate cell 700 includes eight Polyportions.

FIG. 8 is diagram of a layout design with a transmission gate cell forintegrated circuits 800, in accordance with some embodiments. Except asdescribed herein and illustrated in FIG. 8, the description hereinassociated with FIG. 5 is applicable to FIG. 8. In some embodiments, thetransmission gate cell 800 includes three conductive traces in a firstset of conductive traces 802 and two conductive traces in a second setof conductive traces 804, equating to a total of five conductive traces.In some embodiments, the first set of conductive traces 802 and thesecond set of conductive traces 804 are double patterned as M1 portionsof a metal layer. In some embodiments, the first set of conductivetraces 802 and the second set of conductive traces 804 are doublepatterned as five metal lines in M1 portions of a metal layer.

Gate terminals A1, A2, B1 and B2 are formed of Poly portions. Gateterminal A1 shares a first Poly portion with gate terminal A2. The firstPoly portion is electrically connected through a first via V0_2 to afirst M1 metal portion.

Gate terminal B1 in a second Poly portion is electrically connectedthrough a second via V0_3 portion to a second M1 metal portion, thesecond M1 metal portion is electrically connected through a third viav0_1 portion to gate terminal B2 in a third Poly portion. In someembodiments, the transmission gate cell 800 includes at least threeunbroken Poly portions. Unbroken Poly portions are not separatedvertically from one or more other Poly portions. In some embodiments,the transmission gate cell 800 includes five Poly portions.

FIG. 9 is diagram of a layout design with a transmission gate cell forintegrated circuits 900, in accordance with some embodiments. Except asdescribed herein and illustrated in FIG. 9, the description hereinassociated with FIG. 5 is applicable to FIG. 9. In some embodiments, thetransmission gate cell 900 includes two conductive traces in a first setof conductive traces 902 and two conductive traces in a second set ofconductive traces 904, equating to a total of four conductive traces. Insome embodiments, the first set of conductive traces 902 and the secondset of conductive traces 904 are double patterned as M1 portions of ametal layer. In some embodiments, the first set of conductive traces 902and the second set of conductive traces 904 are double patterned as fourmetal lines in M1 portions of a metal layer.

Gate terminals A1, A2, B1 and B2 are formed of Poly portions. Gateterminal A1 shares a first Poly portion with gate terminal A2. The firstPoly portion is electrically connected through a first via V0_2 to afirst M1 metal portion.

Gate terminal B1 in a second Poly portion is electrically connectedthrough a second via V0_1 portion to a second M1 metal portion, thesecond M1 metal portion is electrically connected through a third viav0_3 portion to gate terminal B2 in a third Poly portion. In someembodiments, a bottom portion of the first Poly portion forms a firstdummy transistor. In some embodiments, a MP portion forms a second dummytransistor. In some embodiments, the transmission gate cell 900 includesat least three unbroken Poly portions. In some embodiments, thetransmission gate cell 900 includes six Poly portions.

FIG. 10 is diagram of a layout design with a transmission gate cell forintegrated circuits 1000, in accordance with some embodiments. Except asdescribed herein and illustrated in FIG. 10, the description hereinassociated with FIG. 5 is applicable to FIG. 10. In some embodiments,the transmission gate cell 1000 includes two conductive traces in afirst set of conductive traces 1002 and one conductive trace in a secondset of conductive traces 1004, equating to a total of three conductivetraces. In some embodiments, the first set of conductive traces 1002 andthe second set of conductive traces 1004 are double patterned as M1portions of a metal layer. In some embodiments, the first set ofconductive traces 1002 and the second set of conductive traces 1004 aredouble patterned as three metal lines in M1 portions of a metal layer.

Gate terminals A1, A2, B1 and B2 are formed of Poly portions. Gateterminal A1 shares a first Poly portion with gate terminal A2. The firstPoly portion is electrically connected through a first via V0_2 to afirst M1 metal portion.

Gate terminal B1 in a second Poly portion is electrically connectedthrough a second via V0_1 portion to a second M1 metal portion, thesecond M1 metal portion is electrically connected through a third viav0_3 portion to gate terminal B2 in a third Poly portion. In someembodiments, a bottom portion of the first Poly portion forms a firstdummy transistor. In some embodiments, a MP portion forms a second dummytransistor. In some embodiments, the transmission gate cell 1000includes at least three unbroken Poly portions. In some embodiments, thetransmission gate cell 1000 includes seven Poly portions.

FIG. 11 is diagram of a layout design with a transmission gate cell forintegrated circuits 1100, in accordance with some embodiments. Except asdescribed herein and illustrated in FIG. 11, the description hereinassociated with FIG. 5 is applicable to FIG. 11. In some embodiments,the transmission gate cell 1100 includes three conductive traces in afirst set of conductive traces 1102 and two conductive traces in asecond set of conductive traces 1104, equating to a total of fiveconductive traces. In some embodiments, the first set of conductivetraces 1102 and the second set of conductive traces 1104 are doublepatterned as M1 portions of a metal layer. In some embodiments, thefirst set of conductive traces 1102 and the second set of conductivetraces 1104 are double patterned as five metal lines in M1 portions of ametal layer.

Gate terminals A1, A2, B1 and B2 are formed of Poly portions. Gateterminal A1 in a first Poly portion is electrically connected through afirst via V0_1 portion to a first M1 metal portion, the first M1 metalportion is electrically connected through a second via V0_2 portion togate terminal A2 in a second Poly portion.

Gate terminal B1 in a second Poly portion is electrically connectedthrough a third via V0_3 portion to a second M1 metal portion, thesecond M1 metal portion is electrically connected through a third viav0_4 portion to gate terminal B2 in a fourth Poly portion. In someembodiments, a bottom portion of the third Poly portion forms a dummytransistor. In some embodiments, the transmission gate cell 1100includes at least six Poly portions. In some embodiments, thetransmission gate cell 1100 includes six Poly portions.

FIG. 12 is diagram of a layout design with a transmission gate cell forintegrated circuits 1200, in accordance with some embodiments. Except asdescribed herein and illustrated in FIG. 12, the description hereinassociated with FIG. 5 is applicable to FIG. 12. In some embodiments,the transmission gate cell 1200 includes two conductive traces in afirst set of conductive traces 1202 and two conductive traces in asecond set of conductive traces 1204, equating to a total of fourconductive traces. In some embodiments, the first set of conductivetraces 1202 and the second set of conductive traces 1204 are doublepatterned as M1 portions of a metal layer. In some embodiments, thefirst set of conductive traces 1202 and the second set of conductivetraces 1204 are double patterned as four metal lines in M1 portions of ametal layer.

Gate terminals A1, A2, B1 and B2 are formed of Poly portions. Gateterminal A1 in a first Poly portion is electrically connected through afirst via V0_1 portion to a first M1 metal portion, the first M1 metalportion is electrically connected through a second via V0_2 portion togate terminal A2 in a second Poly portion.

Gate terminal B1 in a third Poly portion is electrically connectedthrough a third via V0_3 portion to a second M1 metal portion, thesecond M1 metal portion is electrically connected through a fourth viav0_4 portion to gate terminal B2 in the first Poly portion. In someembodiments, a bottom portion of the third Poly portion forms a dummytransistor. In some embodiments, the transmission gate cell 1200includes at least six Poly portions. In some embodiments, thetransmission gate cell 1200 includes six Poly portions.

FIG. 13 is diagram of a layout design with a transmission gate cell forintegrated circuits 1300, in accordance with some embodiments. Except asdescribed herein and illustrated in FIG. 13, the description hereinassociated with FIG. 5 is applicable to FIG. 13. In some embodiments,the transmission gate cell 1300 includes two conductive traces in afirst set of conductive traces 1302 and two conductive traces in asecond set of conductive traces 1304, equating to a total of fourconductive traces. In some embodiments, the first set of conductivetraces 1302 and the second set of conductive traces 1304 are doublepatterned as M1 portions of a metal layer. In some embodiments, thefirst set of conductive traces 1302 and the second set of conductivetraces 1304 are double patterned as four metal lines in M1 portions of ametal layer.

Gate terminals A1, A2, B1 and B2 are formed of Poly portions. Gateterminal A1 in a first Poly portion is electrically connected through afirst via V0_1 portion to a first M1 metal portion, the first M1 metalportion is electrically connected through a second via V0_2 portion togate terminal A2 in a second Poly portion.

Gate terminal B1 in a third Poly portion is electrically connectedthrough a third via V0_3 portion to a second M1 metal portion, thesecond M1 metal portion is electrically connected through a fourth viav0_4 portion to gate terminal B2 in the first Poly portion. In someembodiments, a top portion of the second Poly portion forms a dummytransistor. In some embodiments, a bottom portion of the third Polyportion forms a dummy transistor. In some embodiments, the transmissiongate cell 1300 includes at least six Poly portions. In some embodiments,the transmission gate cell 1300 includes six Poly portions.

FIG. 14 is diagram of a layout design with a transmission gate cell forintegrated circuits 1400, in accordance with some embodiments. Except asdescribed herein and illustrated in FIG. 14, the description hereinassociated with FIG. 5 is applicable to FIG. 14. In some embodiments,the transmission gate cell 1400 includes four conductive traces in afirst set of conductive traces 1402 and three conductive traces in asecond set of conductive traces 1404, equating to a total of sevenconductive traces. In some embodiments, the first set of conductivetraces 1402 and the second set of conductive traces 1404 are doublepatterned as M1 portions of a metal layer. In some embodiments, thefirst set of conductive traces 1402 and the second set of conductivetraces 1404 are double patterned as seven metal lines in M1 portions ofa metal layer.

Gate terminals A1, A2, B1 and B2 are formed of Poly portions. Gateterminal A1 shares a first Poly portion with gate terminal A2. The firstPoly portion is electrically connected through a first via V0_A to afirst M1 metal portion.

Gate terminal B1 shares a second Poly portion with gate terminal B2. Thesecond Poly portion is electrically connected through a second via V0_Bto a second M1 metal portion. In some embodiments, the transmission gatecell 1400 includes at least four Poly portions. In some embodiments, thetransmission gate cell 1400 includes six Poly portions.

FIG. 15 is diagram of a layout design with a transmission gate cell forintegrated circuits 1500, in accordance with some embodiments. Except asdescribed herein and illustrated in FIG. 15, the description hereinassociated with FIG. 5 is applicable to FIG. 15. In some embodiments,the transmission gate cell 1500 includes four conductive traces in afirst set of conductive traces 1502 and three conductive traces in asecond set of conductive traces 1504, equating to a total of sevenconductive traces. In some embodiments, the first set of conductivetraces 1502 and the second set of conductive traces 1504 are doublepatterned as M1 portions of a metal layer. In some embodiments, thefirst set of conductive traces 1502 and the second set of conductivetraces 1504 are double patterned as seven metal lines in M1 portions ofa metal layer.

Gate terminals A1, A2, B1 and B2 are formed of Poly portions. Gateterminal A1 shares a first Poly portion with gate terminal A2. The firstPoly portion is electrically connected through a first via V0_A to afirst M1 metal portion.

Gate terminal B1 shares a second Poly portion with gate terminal B2. Thesecond Poly portion is electrically connected through a second via V0_Bto a second M1 metal portion. In some embodiments, the transmission gatecell 1500 includes at least four Poly portions. In some embodiments, thetransmission gate cell 1500 includes six Poly portions.

FIG. 16 is a flow chart of a method of layout design for integratedcircuits 1600, in accordance with some embodiments. The method 1600 isperformed by a programmed processor executing a set of instructions. Inoperation 1602, all conductive traces in a first conductive layer thatare formed using a first mask pattern are positioned in a firstdirection. In some embodiments the conductive traces formed using thefirst mask pattern are parallel metal lines. In operation 1604, allconductive traces in the first conductive layer that are formed using asecond mask pattern are positioned in the first direction. In someembodiments, the conductive traces formed using the second mask patternare parallel metal lines. In some embodiments, the second mask patternis offset from the first mask pattern by less than a pitch of the firstmask pattern.

In operation 1606, all conductive traces in a second conductive layerthat are formed using a third mask pattern are positioned in a seconddirection. In some embodiments the conductive traces formed using thethird mask pattern are parallel polysilicon lines. In operation 1608,all conductive traces in the second conductive layer that are formedusing a fourth mask pattern are positioned in the second direction. Insome embodiments, the conductive traces formed using the fourth maskpattern are parallel polysilicon lines. In some embodiments, the thirdmask pattern is offset from the fourth mask pattern by less than a pitchof the third mask pattern. In some embodiments the first direction at aright angle to the second direction. In some embodiments the firstdirection is horizontal and the second direction is vertical. In someembodiments the first direction is vertical and the second direction ishorizontal. In operation 1610, at least one via is formed toelectrically connect the first conductive layer and the secondconductive layer.

FIG. 17 is a block diagram of a computer system 1700 portion of a layoutdesign for integrated circuits system, in accordance with someembodiments In some embodiments, the computer system 1700 executes a setof instructions to perform the method of layout design for integratedcircuits 1600 (FIG. 16). Computer system 1700 includes a hardwareprocessor 1782 and a non-transitory, computer readable storage medium1784 encoded with, i.e., storing, the computer program code 1786, i.e.,a set of executable instructions. The processor 1782 is electricallycoupled to the computer readable storage medium 1784 via a bus 1788. Theprocessor 1782 is also electrically coupled to an I/O interface 1790 bybus 1788. A network interface 1792 is also electrically connected to theprocessor 1782 via bus 1788. Network interface 1792 is connected to anetwork 1794, so that processor 1782 and computer readable storagemedium 1784 are capable of connecting and communicating to externalelements via network 1794. The processor 1782 is configured to executethe computer program code 1786 encoded in the computer readable storagemedium 1784 in order to cause computer system 1700 to be usable forperforming a portion or all of the operations as described with respectto the method of layout design for integrated circuits 1600 (FIG. 16).

In some embodiments, the computer program code 1786 includes aninstruction 1796 to position all conductive traces on a first conductivelayer using a first mask pattern in a first direction. An instruction1797 positions all conductive traces on the first conductive layer usinga second mask pattern in the first direction. An instruction 1798positions all conductive traces on a second conductive layer in a seconddirection using a third mask pattern and a fourth mask pattern. Aninstruction 1799 electrically connects conductive traces in the firstconductive layer and the second conductive layer using at least one via.In some embodiments, the first direction is at a right angle to thesecond direction.

In some embodiments, the processor 1782 is a central processing unit(CPU), a multi-processor, a distributed processing system, anapplication specific integrated circuit (ASIC), and/or a suitableprocessing unit.

In some embodiments, the computer readable storage medium 1784 is anelectronic, magnetic, optical, electromagnetic, infrared, and/or asemiconductor system (or apparatus or device). For example, the computerreadable storage medium 1784 includes a semiconductor or solid-statememory, a magnetic tape, a removable computer diskette, a random accessmemory (RAM), a read-only memory (ROM), a rigid magnetic disk, and/or anoptical disk. In some embodiments, using optical disks, the computerreadable storage medium 1784 includes a compact disk-read only memory(CD-ROM), a compact disk-read/write (CD-R/W), a digital video disc (DVD)and/or Blu-Ray Disk.

In some embodiments, the storage medium 1784 stores the computer programcode 1786 configured to cause computer system 1700 to perform theoperations as described with respect to the method of layout design forintegrated circuits 1600 (FIG. 16).

In some embodiments, the storage medium 1784 stores instructions 1786for interfacing with external components. The instructions 1786 enableprocessor 1782 to generate operating instructions readable by a systemfor performing the method of layout design for integrated circuits 1600(FIG. 16).

Computer system 1700 includes I/O interface 1790. I/O interface 1790 iscoupled to external circuitry. In some embodiments, I/O interface 1790includes a keyboard, keypad, mouse, trackball, trackpad, and/or cursordirection keys for communicating information and commands to processor1782.

Computer system 1700 also includes network interface 1792 coupled to theprocessor 1782. Network interface 1792 allows computer system 1700 tocommunicate with network 1794, to which one or more other computersystems are connected. Network interface 1792 includes wireless networkinterfaces such as BLUETOOTH, WIFI, WIMAX, GPRS, or WCDMA; or wirednetwork interface such as ETHERNET, USB, or IEEE-1394.

Computer system 1700 also includes inductive loop interface 1795 coupledto the processor 1782. Inductive loop interface 1795 allows computersystem 1700 to communicate with external devices, to which one or moreother computer systems are connected. In some embodiments, theoperations as described above are implemented in two or more computersystems 1790.

Computer system 1700 is configured to receive information related to theinstructions 1786 through I/O interface 1790. The information istransferred to processor 1782 via bus 1788 to determine correspondingadjustments to the transportation operation. The instructions are thenstored in computer readable medium 1784 as instructions 1786.

Some embodiments include a method. The method includes positioning afirst set of conductive traces in a first direction, manufacturing asecond set of conductive traces by a first mask pattern, andelectrically coupling, by at least a first via, at least one conductivetrace of the first set of conductive traces to at least one conductivetrace of the second set of conductive traces. The first set ofconductive traces is in a first layer of an integrated circuit. Thesecond set of conductive traces is in a second direction different fromthe first direction. The second set of conductive traces is in a secondlayer of the integrated circuit. The second layer is different from thefirst layer. A conductive trace of the second set of conductive tracesis part of a first dummy transistor.

Some embodiments include an integrated circuit. The integrated circuitincludes a first set of conductive traces in a first layer of anintegrated circuit, a second set of conductive traces in a second layerof an integrated circuit different from the first layer, and a first viaelectrically coupled between a first conductive trace of the first setof conductive traces and a first conductive trace of the second set ofconductive traces. The first set of conductive traces extends in a firstdirection. The second set of conductive traces extends in a seconddirection different from the first direction. A second conductive traceof the first set of conductive traces is part of a first dummytransistor.

Some embodiments include an integrated circuit. The integrated circuitincludes a first PMOS transistor, a first NMOS transistor, a first dummytransistor, a first set of conductive traces extending in a firstdirection in a first layer of an integrated circuit, and a second set ofconductive traces extending in a second direction in a second layer ofthe integrated circuit different from the first layer. The first PMOSincludes a gate. The first NMOS transistor includes a gate. The firstconductive trace of the first set of conductive traces is the gate ofthe first PMOS transistor. A second conductive trace of the first set ofconductive traces is the gate of the first NMOS transistor. A firstconductive trace of the second set of conductive traces and the firstconductive trace of the first set of conductive traces are configured toelectrically couple the first PMOS transistor and the first NMOStransistor as a first transmission gate.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A method of manufacturing an integrated circuitcomprising: positioning a first set of conductive traces in a firstdirection, the first set of conductive traces being in a first layer ofthe integrated circuit; manufacturing a second set of conductive tracesby a first mask pattern, the second set of conductive traces being in asecond direction different from the first direction, the second set ofconductive traces being in a second layer of the integrated circuit, thesecond layer being different from the first layer; and electricallycoupling, by at least a first via, at least one conductive trace of thefirst set of conductive traces to at least one conductive trace of thesecond set of conductive traces, wherein a conductive trace of thesecond set of conductive traces being part of a first dummy transistor.2. The method of claim 1, further comprising: positioning a third set ofconductive traces in the first direction, the third set of conductivetraces being in the first layer of the integrated circuit.
 3. The methodof claim 2, further comprising: positioning a fourth set of conductivetraces in the second direction, the fourth set of conductive tracesbeing in a third layer different from the first layer.
 4. The method ofclaim 3, further comprising: electrically coupling, by at least a secondvia, at least a conductive trace of the third set of conductive tracesto at least a first conductive trace of the fourth set of conductivetraces.
 5. The method of claim 4, further comprising: electricallycoupling, by at least a third via, at least a second conductive trace ofthe fourth set of conductive traces to the conductive trace of the thirdset of conductive traces.
 6. The method of claim 5, wherein the firstconductive trace of the fourth set of conductive traces corresponds to agate terminal of a first n-type transistor, the second conductive traceof the fourth set of conductive traces corresponds to a gate terminal ofa first p-type transistor, and the first n-type transistor and the firstp-type transistor being part of a first transmission gate.
 7. The methodof claim 1, further comprising: electrically coupling, by at least asecond via, the at least one conductive trace of the first set ofconductive traces to at least another conductive trace of the second setof conductive traces.
 8. The method of claim 7, wherein the at least oneconductive trace of the second set of conductive traces corresponds to asource terminal of a first n-type transistor, the at least anotherconductive trace of the second set of conductive traces corresponds to adrain terminal of a first p-type transistor, and the first n-typetransistor and the first p-type transistor being part of a firsttransmission gate.
 9. The method of claim 1, wherein the first directionis perpendicular to the second direction.
 10. An integrated circuit,comprising: a first set of conductive traces in a first layer of anintegrated circuit, the first set of conductive traces extending in afirst direction; a second set of conductive traces in a second layer ofan integrated circuit different from the first layer, the second set ofconductive traces extending in a second direction different from thefirst direction; and a first via electrically coupled between a firstconductive trace of the first set of conductive traces and a firstconductive trace of the second set of conductive traces, wherein asecond conductive trace of the first set of conductive traces is part ofa first dummy transistor.
 11. The integrated circuit of claim 10,further comprising: a second via coupled between a second conductivetrace of the second set of conductive traces and the first conductivetrace of the first set of conductive traces.
 12. The integrated circuitof claim 11, wherein the first conductive trace of the second set ofconductive traces corresponds to a gate terminal of a first n-typetransistor, the second conductive trace of the second set of conductivetraces corresponds to a gate terminal of a first p-type transistor, andthe first n-type transistor and the first p-type transistor being partof a first transmission gate.
 13. The integrated circuit of claim 10,further comprising: a third set of conductive traces extending in thefirst direction, the third set of conductive traces being in the firstlayer of the integrated circuit.
 14. The integrated circuit of claim 13,further comprising: a fourth set of conductive traces extending in thesecond direction, the fourth set of conductive traces being in a thirdlayer different from the first layer.
 15. The integrated circuit ofclaim 14, further comprising: a second via coupled between a firstconductive trace of the third set of conductive traces and a firstconductive trace of the fourth set of conductive traces.
 16. Theintegrated circuit of claim 15, further comprising: a third via coupledbetween the first conductive trace of the third set of conductive tracesand a second conductive trace of the fourth set of conductive traces.17. The integrated circuit of claim 15, wherein the first conductivetrace of the fourth set of conductive traces corresponds to a sourceterminal of a first n-type transistor, the second conductive trace ofthe fourth set of conductive traces corresponds to a drain terminal of afirst p-type transistor, and the first n-type transistor and the firstp-type transistor being part of a first transmission gate.
 18. Anintegrated circuit, comprising: a first PMOS transistor, comprising agate; a first NMOS transistor, comprising a gate; a first dummytransistor; a first set of conductive traces extending in a firstdirection in a first layer of an integrated circuit, a first conductivetrace of the first set of conductive traces being the gate of the firstPMOS transistor, and a second conductive trace of the first set ofconductive traces being the gate of the first NMOS transistor; and asecond set of conductive traces extending in a second direction in asecond layer of the integrated circuit different from the first layer,wherein a first conductive trace of the second set of conductive tracesand the first conductive trace of the first set of conductive traces areconfigured to electrically couple the first PMOS transistor and thefirst NMOS transistor as a first transmission gate.
 19. The integratedcircuit of claim 18, further comprising: a first via coupled between thefirst conductive trace of the first set of conductive traces and thefirst conductive trace of the second set of conductive traces; and asecond via coupled between the second conductive trace of the first setof conductive traces and the first conductive trace of the second set ofconductive traces, wherein a third conductive trace of the first set ofconductive traces is part of the first dummy transistor.
 20. Theintegrated circuit of claim 18, further comprising: a second PMOStransistor, comprising a gate; a second NMOS transistor, comprising agate; a first via coupled between a third conductive trace of the firstset of conductive traces and a second conductive trace of the second setof conductive traces; and a second via coupled between a fourthconductive trace of the first set of conductive traces and a secondconductive trace of the second set of conductive trace, wherein thesecond conductive trace of the second set of conductive traces and thethird conductive trace of the first set of conductive traces areconfigured to electrically couple the second PMOS transistor and thesecond NMOS transistor as a second transmission gate, the thirdconductive trace of the first set of conductive traces is the gate ofthe second PMOS transistor, and the fourth conductive trace of the firstset of conductive traces is the gate of the second NMOS transistor.